Situation
Solution
Fan speed too high of one fan of the LDM
Malfunctioning fan. Replacement needed. Remove the fan from the LDM and replace the fan. See service procedure "Removing a fan from an LDM".
If problem persist replace the LDM. See service procedure "Replacing a Laser Drive Module".
Fan speed error on both fans of the LDM. Malfunction LDM.
Replace the LDM. See service procedure "Replacing a Laser Drive Module".